Drools Eclipse cannot show Rete view

Question

I am trying to study Drools to build a Rule Based System.

I installed Drools plugin for Eclipse.

I created a new Drools project with sample, but when I opened Sample.drl file then select "Rete Tree" I got an error

"Rete Tree Build Error!

Reason: java.lang.Exception: Unable to parse rules to show RETE view! java.lang.ClassNotFoundException: org.drools.ecj.EclipseJavaCompiler cannot be found by org.drools.eclipse_7.47.0.Final"

My version:

Eclipse version: J2EE 2019-03

Drools version: 7.47.0

I already configured the Drools Runtime.

Could you help me

Answer 1

Unfortunately, the drools-tools plugin for Eclipse was broken in the 7.47.0.Final release process due to a delivery error.

Please upgrade to 7.48.0.Final

After a more thorough investigation, the situation is not that simple.

The latest working version is 7.46.0.Final, and as we're planning to deprecate the Eclipse plugin, that'll be our latest release.

It’s possible to use a different version of a plugin and runtime. As we haven’t added any feature in the plugin it should work the same if you use the 7.46.0.Final plugin with another runtime (7.49 or even 7.50)

The documentation will be updated accordingly.